Saw sharpening machine



Aug. 2, 1949. v KERs w EVTAL 2,477,880

I SAW SHARPENING MACHINE Filed June 29, 1945 I 7 Shee'ts-Sheet 1 1949- I K-ERSHAW ET L 2,477,880

SAW SHARPENI NG MACHINE Filed June 29, 1945 '7 sheets-sheet 2 Aug. 2, 1949. H. KERSHAW ET AL SAW SHARPENING MACHINE 7 Sheets-Sheet 3 Filed June 29, 1945 WW W Aug. 2, 1949. H. KERSHAW ET AL 7 2,477,880

SAW SHARPENING MACHINE Filed June 29, 1945 7 Sheets-Sheet 4 V NW 5 M F 9 m: 7 bevy Ju -1: R

' H. KERSHAW ETAL Aug. 2, 1949.

SAW SHARPENING MACHINE 7 Sheets-Sheet 5 Filed June 29, 1945 Henry Ke aslzauf. fllberzf FPziyo Aug. 2, 1949. H. KERSHAW ET AL SAW SHARPENING MACHINE Filed June 29, 1945 7 Sheets-Sheet 6 Aug. :2, 1949. HJKER SH I AW ETAl 2;477,8 80 I I SAW SHARPENING MACHINE I I Filed am 29, 1945 I 7 Sheets-Sheet 7 Patented Aug. 2, 1949 AT T OFFICE SAW 'SHARPENING ll/IACI IINE Henry Kershaw, Belleville, Albert F. Pityo, Clifton, and Harry Butterfield, Maplewood, N. J., assignors, by mesne assignments, of one-half to said HenryKe rshaw, one-fourth to said Albert vF. Pityo, and one-fourth to said Harry Butter- Application June 29, 1945,,seria1 No. 602,180

(c ts-40 I '17 Claims.

Our invention relates to a machine for sharpenins saws. r e

An important object of the invention is to provide a machine which will sharpen various types of saws, such as hack saws, wood saws, band saws or circular saws. V g

A further object of the invention is to provide a machine of the above mentioned character which is adjustable for cutting the desired rake on the saw tooth. V A further object of theinvention is to provide a machine of the above mentioned character which will cut the desiredzset'or transverse angle on the saw teeth. g

A further, object of the invention is to provide amachine. of the above "mentioned character which is adjustable to regulate the throw of the rotary cutter or grindingwheel to compensate forthe variance in size of the saw teeth to be ground, as well-as to compensate for'the change in diameter of the rotary cutter or grinding wheel, due to wear upon the same, or the use of rotary grinding wheels, of different diameters.

A further object of the invention is to provide means to feed the saw longitudinally by engaging-the teeth of the'saw. ;A further object of the invention is to provid saw feeding means of the above mentioned character which can be accurately adjusted to properly feed sawshaving teeth ofdifferent longitudinal length. t

A further object of the invention is to provide means for effecting a steplby step feed of the saw and at the same time positively holding the saw against backward movement.

A further object of the invention is to provide a machine of. the above mentioned character which isinthe. nature of. an attachment to be mounted upon the table of a drilL-rand driven by the spindle of the drill, whereby the-difierent speeds of the spindle may be utilized to drive the rotary cutter or grinding wheel and compensate for the change in diameter of the cutter or grinding wheel, due to wear or the like.

vA further object of the invention is to provide means for covering the rotary cutter or grinding wheel, thusreducing liability of accidents.

A further object of the invention is to provide a machine of the above mentioned character which is relatively simple in construction and F In the accompanying drawings, forming ,a part 2 of this application, and in which like numerals are employed to designate like parts throughout the same.

Figure 1 is a perspective view of a saw sharpening machine embodying our invention, showing the same applied to a-drill press, 7

Figure 2 is a plan view of the same,

Figure 3 is a side elevation of the same,

Figure 4 is an end elevation of the same,

Figure 5 is a perspective view of the driving means and associated elements separated from the casing,

Figure 6 is a side elevation of the saw feeding pawl, V

Figure 7 is an exploded perspective view of the pawl and associated elements, I

Figure 8 is a horizontal section taken on line B-8 of Figure 3,

Figure 9 is a vertical longitudinal section taken on line 9-9 of Figure 2,

v Figure 10 is a transverse vertical section taken on line Iii-10 ofFigure 3,

Figure 11 is a similar view taken on line I ll I of Figure, 3,

;' Figure 12 isv an exploded perspective view of the saw holding and guiding means,

1 Figure 13 is a transverse section taken on line I 3I3 of Figure 2,

, Figure 14 is a plan view, partly diagrammatic, of the-saw holding and guiding means, illustrating the horizontal adjustment of the same,

Figure 15 is a side elevation, partly diagrammatic, of the saw holding and guiding means, illustrating the vertical adjustment of the same,

Figure 16,is:a plan view, partly diagrammatic, of the saw sharpening machine, showing the same sharpeninga band saw,

Figure 17 is a side elevation of the same,

Figure 18 is a side elevation of a modified form of the invention, showing a machine for sharpening a circular saw,

Figure 19 is a plan View of the same, parts in horizontal-section,

Figure 20 is an end elevation of the same,

Figure 21 is a perspective view of the pawl covering plate, a

Figure 22 is a plan view of the grinding wheel and saw, illustrating the horizontal angular adjustment of the saw blade,

Figure 23 is aside elevation of a grinding wheel illustrating the vertical adjustment of the saw blade,

Figure 24 is a horizontal transverse section through oneofthe teeth, showing the'edges of the tooth cut at an incline,

Figure 25 is a similar view through the edges of the tooth cut at a right angle,

Figure 26 is a diagrammatic view showing the grinding action when the radial wall of the tooth is held perpendicular and in alignment with the grinding "end of the grinding wheel,

Figure 27 is a similar view showing the saw shifted so that its center is to one side of the grinding end of the grinding wheel and the radial Wall of the tooth is inclined with respect to the l perpendicular, and

Figure 28 is an enlarged fragmentary perspective view of the saw.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of our invention, the numeral l designates a drill as a whole, comprising a vertical hpost ilil, :carming a table [2. Mounted upon the top of the post #0 is a vertical spindle 23, carrying a chuck M. The spindle I3 is driven by a motor through the medium 'of variable speed gearing $6. The present invention, for the purpose of illustration, will be described as applied to this drill,='but the invention may be applied to any other suitable iormof drill. it may be used without the-drill, and driven by any suitable means.

It is preferred-thatou-r grinder be made in the nature -df an attachment to be used with the drill, Jfor 'convenience in dlamping the same in place and for driving the :same. Our grinding machine includes "a housing -11, having a top I'B which is cut away at [9 for providing an opening or passage 20, which extends to the longitudinal edge of the top l8, as shown. This passage receives a ro'tary grinder, to be described. The top also includesa vertical inclined top portion :21, which leads'to the passage 2'0 and extends upwardly toward this passage. "T -he nousing l provided at its :bottom with horizontal flanges 22, having openings 23, for receiving bolts 2'4 exten'ding thro'ugh slots in-the table [2 and Serving to clamp thehousing l-Pto the table [2.

The top I of the housing has a vertical be'aring 26, receiving a vertical shaft 21,'a1so .Ejournalle'd :at its lower end in a fixed bearing 28. The shaft 21cannot.move longitudinally with relation to ith'e housing H :and :carries a stop ring 29, clamped thereto, and engaging the topofthe hearing as. The upward movement a of the shaft is prevented by a horizontal ibe'vel gear 160, rigidly mounted ".upon this shaft and engaging a bearing element for washer 131 in turn engaging the lower Lender the verticalibearing 126. The-upper end :of .the shaft 2?! is inserted into ="the chuk hi andfills :therefore drivenby Ithe spindle 43. The horizontal bevel gear 39 engages a vertical hev 'el gear 3!, arranged beneathlit, andthis bevelgear 3| is rigidly mountedaupon az'horizontalilongitudinal shaft :32, journalled in fixed bearings 33 ended.

The numeral 35 designates a tramsverse' -vertical swinging supp'ortJor carriage, :pi'ovided ation'e end with a sleeve 36, pivoted upon the shaft 3-2,:a;nd held. against :longitudin'alimovement by the bearin'gs 83'and 34. AtitsPfree end, the carriage 35 has a long sleeve or bearing 31, receivin'gia horizontal rrotatableshait tor spindle '38. Theshaft or spindle 38 has a rotary cutter for grinding wheel 39, suitably mounted thereon, :in oon'centrio relation'theretounear'nne-end, and'ithe shaft or spindle es extends rfor a short distance beyond this cutter or grinding wheel. A stop ring at 'is suitably clamped upon the opposite end of the-sha'ftor spindle '38, and r a spacing ring WI 'is arranged between the 'cutter or grinding wheel 4 39 and the opposite end of the sleeve or hearing 31. The shaft or spindle 38 cannot move longitudinally with respect to the sleeve or bearing 31 but is rotatable therein. The shaft or spindle 38 remains horizontal atiallitimesi and the cutter or grinding wheel 39 remains perpendicular or vertical at all times and extends transversely of the axis of rotation of the shaft 38 and at a right angle .to this axis of rotation. The cutter or grinding wheel 39 is circular and has flat parallel :faces 42 and 43, perpendicular to the axis of rotation of thes'hatfit or spindle 38. The cutter or grinding wheel has a periphery 44 which is beveled-or inclined, corresponding to the shape of the saw teeth to be ground.

Disposed upon the outer side of the cutter or grindingwheel is a pulley 45, rigidly mounted upon the end of the shaft 38, and removable from this shaft. This pulley is driven by a belt 46, engaging a larger pulley 41, in turn rigidly mounted upon the shaft 3 2. The I support or carriage 35 is concentrically pivoted with respect rto thezpulley 11:1.

:Rigidlyzmourited llpfln the vertical shaft 2?! beneath itherhm i-zontal bevel gear 311, is a worm 18, disposed to engage a worm wheel ill, which is rigidly mounted upon a :horizontal longitudinal shaft 511., journalled :in nixed bearings L5! and 52.

.The shaft 5x; .18 zpalrallel with the shaft 32.

Rigidly mounted upon the shaitt fill isia cam 53, having a high point 254, arranged to engage a rounded :heaxl 55, nanriedcby the lower end :of an adjustable screw :56, shaming :screw th-reade'd engagement within an opening 51, if'orin'ed in the support or carriage s5. Thissadjustableiscrew-fifi is zlocked in pnsitiunibya lock nut 58. 'T-he purpose of the adjustable screw 55 is -.to regulate the wertical reflective :grintling movement of the cutter ror grinding wheel 39. when the adjustable screw 55 screwed downwardly with relathan to the support for zcarriage E5, the support or marriage will ihave .a higher "starting point and also a higherstopping:point. With the diameter of the cutter 1'01 grinding wheel :39 :being constant, :the afilected grinding action .of the grinding wheel can therefore bezadjus'ted, :torcompensate for the 'depth of cthezsaw-touth ."to he ground. The screw-56 is also :adjustcd :to compensate -for the-change in'diam'eter :of the cutter :or grinding wheel, :as 'it wears down, or 'to compensate for the use of grinding wheels of difierent-iiiameters. .Thecu-tter orgrinding' wheel 391mlstdoe'dressed at intervals, for maintaining :Tllh'e :proper Zbevel (if the periphery M, rand reducesith'e diameter of the grinding wheel, which :ls z nomperrs'ated'rfcr by adjusting 'the screw "56, as explained. The support .or --carriage 35 is moved downwardly by aspriingafiSpengaging the itopaof the carriageand a disc 611-, engaging an adjustable screwrhaving screw threaded iengagement within :-an mp'ening formed in :the tap 't8. The :tens'i'on of the sprin'gd'ifi mayibe regulateduand this spring moves the support or marriage :35 dnwnwardly ian'd causes the head closely afoll'ow the cam 53.

Theznumerarfitziesignates a horizontallyzangularly "adjustable ibracket, :ineludlng :a horizontal base Mr-and a wertical web 94. "The horizontal base :has circularly'curved slotsfififinand the web 164 thas"circularlyrcurved slots 55. "The slots 66 .receive-rbolts fi 'l which are tapped 'irito the top 8. A saw holding and guidingdevise 'lifl is provided, comprising vertical or upstanding p'la/tes $9 and 11), ha'ving their 'inner faces contating,as shown. The curved slots 65 receive bolts -"FI,'wvlirdh are tapped into the =plate d9; The "assembled plates 89 and "I8 may therefore be turned with respect' to the vertical web 84 for angularly adjusting theassembled plates 89 and I8. The plate 18 is provided with openings I2 for receiving centering pins I3, for insertion within openings I4, formed in the plate 89. The plate I8 is provided near its upper end with openings I5 for receiving set screws I8 for screw threaded engagement within openings 11 formed in the plate 89. The set' arranged beneath the bottoms of the plates 89and I8, adjacent to their forward ends, and are secured to the plates 89 and I8 by screws 81, as shown. I

Mounted upon the support-plate BI is a circular pawl controlling or covering disc 88, eccentrically pivoted upon the support-plate 8| at 89. The upper face of this pawl controlling or covering disc is flat, while its lower face is beveled adjacent to its periphery, as shown at 98. The upper face of the disc 88 is at the elevation of the upper face of the support-plate 88. The disc 88 and the support-plate 8| are spaced from the forward support-plate 86, providing a passage 9 I, which leads to notches 92, formed in the plates 89and I8. The upstanding plate I8 is provided upon its inner face with a recess 98, the side wall of which is perpendicular to the horizontal. This recess extends from a shoulder 94 and passes through the bottom of the upstanding plate I8. At its longitudinal center, the upstanding plate I8 is provided with a vertical recess 95, receiving a guide. plate or element 98, having a notch 91 at its lower end, to register with the notches 92. The guide plate 98 is vertically adjustable and is clamped in the selected adjusted position by set screws 91, tapped into the upstanding plate 7 8. It is thus seen that the upstanding plates 89 and I8 and associated elements constitute means for holding and guiding a saw 98, which may be a hack saw. Thissaw is arranged on edge within the recess 93. and its teeth rest upon the disc 88 and front supportplate 86. The saw 98 is thinner than the recess 93.

Means are provided to effect a step by step longitudinal feed of the saw 98. This means comprises a sleeve 99, pivoted upon a horizontal transverse stud I88, anchored to the bearing 33. This sleeve carries a generally horizontal arm I8I, arranged above and in engagement with a cam I82, having a high point I83. This cam is rigidly mounted upon the shaft 58. The sleeve 99 is provided with an upstanding arm I84, having a horizontal extension I85 at its upper end, and a pawl I88 is pivotally mounted upon this horizontal extension, at I81. The pawl I88 faces upwardly and is urged upwardly by a spring I88, mounted upon an extension I89 carried by the arm I84. The arm I84 is swung in one direction to cause the arm I 8| to closely follow the cam I82, by a'rectangular coil spring H8. The pawl I86 is arranged to successively engage the'teeth of the saw 98, passing-into the space 9I,for this purpose. The pawl I88 is arranged beneath the disc 88 and this disc regulates the efi'ective'actioii'" of the pawl, upon each stroke, so'that it will feed the saw each step, throughout the entire length of the tooth of the saw, depending upon the particular length of such tooth. When the pawl I 88' moves forwardly it is beneath the disc 88 and is covered thereby and as it approaches the end of its forward stroke, it rides off of the beveled face 98 of the disc 88 and rises to engage with the: selected tooth of the saw, and completes its'for-' ward stroke while engaging such tooth, and thus feeds' the saw a step corresponding to the length" of the tooth. The entire stroke of the pawl portion of the pawl stroke, but releases the pawl;

for engagement with the saw tooth, for the re,- mainder of the pawl stroke.

off 'ofthe disc at different points in its forward:

stroke, whereby the effective feeding movementof the pawl while engaging the saw tooth may be regulated, corresponding to the length of the saw tooth." The disc 88 is provided with a scale I II for coaction with a fixed pointer H2, to indicate the extent of adjustment of the disc 88.

Means are provided to prevent the back feedl of the saw 98 and to hold the saw in engagement with the face of the recess 93, comprising a 'saw' clamp H3, projecting through the notch'92 of.

the plate 89, and pivoted by a pin I I4 uponan arm: II5, carried by the upstanding plate 89. The; saw-engaging end of the clamp H3 i preferably rounded and the clamp vI I 3 is swung inwardly to-" ward the clamping position by a plunger II8, slideable within a cylindrical opening I I! formed in the upstanding plate 89. This plunger is urged inwardly by acompressible coil spring II8, held in place by a screw threaded plug I I9, clamped in position by a set screw I28. The clamp II3 permits of the forward movement of the saw 98 but positively checks its rearward movement. The clamp ,I I3 and arm I I5 also extend through a vertical opening or notch II5 formed in the vertical web 84 and this notch I I5 is suificiently large to permit of the movement of the elements I I3 and I I5 therein, when the plate 89 is vertically angularly adjusted with respect to the vertical web 88- The grinding wheel 39 must be dressed or sharpened at intervals and for this purpose we provide an anvil I2I, attached to the housing- Ilt. This anvil serves to support or guide the wheet dressing tool. The anvil is covered by a housing or guard I23, pivoted to the housing I1 to swing horizontally, as shown at I24. This housing also covers a part of the grinding wheel. Thebracket 82 also has a recess I25 for receiving a portion of the disc 88.

The horizontal circularly curved slots 88 are concentric with the plane of the face 42 and the vertical circularly curved slots 85 are also concentric with the plane of this face 42. The operation of the machine is as follows: The hack saw 98 is inserted within the recess 93, upon edge, with its teeth resting upon the disc 88 and front support plate 88. The guide or holding plate 98 is moved downwardly into. proper engagement with the upper edge of the saw 99' and is then clampedin the adjusted position. The saw is longitudinally adjusted so that its leading tooth is at the passage 9I to be engaged by the grinding wheel, when it rises. If the upstanding plates 89 and I8 are perpendicular; and parallel with the axis of rotation of the grinding By turning the disc; 88 upon its eccentric pivot 89, the pawl will ride" amine e se. eg tpisfmsiujn, wh n it; e'"re.

tki. (and es: the; ngle; or; wail: as t f gri ej. he: isiangllailly adjusted in aver: 1 G5 1 Ii K' neI E a n 3; a (1 h s wil sense he vy a ll 'I tbl he 'r'ilitalong the line, lljig ure n''u,cf1 1gftherake., The 1 2g 1' cnt byithe 12min. rime erind ne. heel ih i ay it, may. be ho izontal -f afieillarly adqqs' eii; g:

e; lently, of; 'thejv'eitieal] angular ad nstme iil Qr se ere e fi e e t riee hq nam ng ringed. lineman. '2 is qtatmg and hisiotetwn i impart d. to the bevel ear d'fivin'g -he vel g ea 'grffl rg'tating shaft eietesrsiiait or s mil h of the'gea'ring inc 1 e1, ,tgt w in '4,.; :9tetine worzn"'iv,lieel hi nin ate shawl; he new ei-ates aiia rn en at. 54, 1e a h n 51? hi h hiites. h ar ia rsunpqrt .5 u ardly, ye iheft ie Hind I p I wit e wal s and 23. or the ea ing" b en and next trailing t'qoth." The' ie n 5i1l$l r m n Jl i 1 .24 I 5Al he WT F iid seq fis 9 h lane; ms i n and; t is diiwnw pimqv eim ilim 'QQ' by he heasi. e' eii'i 'e l w h'i Q li'i d Phil e? he win-5L 'The'hieh p jn 54.,Qij heceni 3.1 22 ihim' h poi o fing n 02, an g em h pdiht 54'" will'i ais e lower e carriage as b the f t-i1 Wm? 1 .3 fiuetsi t epe l; Th9 pawns iip w'in the re 01; contracted s a n ath n: 88, Fi ure When their libi-nt' I0}! 'c'f thece ih IIIZ 'eng ages, theaim IQ 'I; thf'lei 5 is u ned mw idlr @2121 new I'M swung 'fm-w army while the spring I I18. is pressi'ng"the pawl I6 6 upwardly The pawl moved forwardl "and 1 rises during this forward movement and engages the wall lgfi gf, the tooth. I21 and then moves the saw a step fer a distance equal td th horizontal'leng th Qf the t opth." when the'high 150m :53 passes bleydnd the" ar my; the sleeve 39 is turned inth'e opp csite direc t qr r and the arm IGqswings rearwardiy and the' pa I06 moves' 'rea'rwardl'y and: is lowered by the beveled face 90 and is again c dveredby the disc 32L Each toothis ground or sharpened, and the saw fed a' step, so that the snccessive tQqth is. grcun'cl or sharpened, and the cycle o f operatiqri is automatically repeated. After the sha rpen' ing 'df-"th'e' saw is d'lhpl'eted it .miwjbej readily withdrawn by' a forward movement.

The machine can alsq be used for sharpening bandsaws} In Figure 16; wg haye shqwpbsgqlj; an arrangement. The nlilill'leljal lafl designates a; band saw, which is arrangedfgenerallvhqrizpm tally on edge with its teeth resting;upcn grpoyed, vertical wheels I3 I carried by siiitaple suppqrts' Th ji d s l i i tl q iz'pn al. Wh els. I321 which are suitably," sap 'q t w t e lw elf .9 nto en gemen nemg ged #9 5 :the. ton 1 am 1 llRpQ i -nlh i in am 8, a e sna z li tem he esieeei e waste as "Anr ipn, Qr n anew llle 2l i BW 1 nd J l i h reg s 93 he. snppgrt-plates 8! and 86 are 'd to the fupstandine plates 6 ,9 and I racl t 6; again" applied mot le t Ia. Alf'qthefiparts, 'cf the apparatus remain iqegmgi with thdse Shown and described 1; e51; lciiiqn. withtlie. first fprin cf the'inventign,

atedvin the identical manr, sld siii sd fi eq i i h he h rnew. 1. If 5 blad 8 When he p at s, 6,91 and we e an larlv ad s d as. describedtini .1-

' with 'thefifirst fqrrrici the inventicn, the, have to be adiustedjam dgrding lx, ahd t hesel wheels will be suppgrted rlmf enswnicn pe m t i ni 'maphinej, wi h light odifica cn, e

sed tqs'harpen or grind circular saws.

q f the nvent on. is, how in Fi ures s ie n th s modifiq tion e p i j i e' new, 6.5 end fll d e en r e hank and th'b'racket' 62 aire'omitted. In Figures" 18 t m ii ive h vnume al 3 iena'tes hrack etg havingfa horizgntal base I34 anda 'v er nqar'wep rat. h has 13; has circnlarly curved slbts I36, c'orrespcnding to the slots 55 Figure 12."""I{h slots I 36 receive bolts I31} which are tapped into thetop la." The bracket [331s there fare fienzentan angiilar ly' adjiistahle." verti plate 138', for receiving the headed end of a stud I742,-' Mounted upon the stud I42 isian adaptor I43; having an opening I45- to receivethe' stud and having a reduced circular extension I46 'tb enter the opening of-a circular saw I 41. The extensidn I46 is slightly thinner than the saw I41. Alsleeve I4 8 is'preferab1y formed integral with the adaptor 14?. The mimem MQdSig? nates an inner washer and I50 an cuter washer, and aesp'ring I5I is arranged between these wash ers-Z The mat I52 has screw threadedenga gmentv with the outer end'oi the stud IQ] 133 screwing up the niit I52, the'studis' clamped against. the plate I-38-s0 that it cannot be abet; dentally displaced and the spring I 5| compressed so: thatthe innerwasher Mil-is yieldingly clamped against the face of the circular saw I 41. This prcdncessnfiicient frictional engagement to p'r v'entiimpro'per turning mcvement 0f the saw but perrnjts the saw on be fed in astep b yistep man-i ner; w nemak r lasgs; provided adjacentto the I3 1; witha liorizcntal gropve I53; to. receive. at a'wi cpntijgl ngj .1: cbvering. plate I54, having screw tn; dedope'nings ,I 5 5 t'o repeivehplts I55 within, elongated slots I51, formedfin l e' i h Pl v h i horiz n: ii ii fii s le h l et i 5% a n. e a f" he-l w ees; loth s beveled-fit 32 fi xili iqn x nd e ther vwl. lfir s eulete itsest en s xplaine zml pnn necigion withgthe disc,385 ll otherparts .cf the eefe'ate new; e si t cal i emose hqwa and deem-mama wsi qniwimme r t f mor i 14. s?" e ea en eel ieet' 5 ti iiet si i The operation of this form of .the machine is as follows:

The plate I38 may be adjusted so that thelongitudinal center of the stud I42 will be in substantial alignment with the face 42 of the grinding wheel 30. The wall I59 of the tooth I60 being ground will then be radial and perpendicular, as indicated by the line I60, Figure 26. All walls I59 are radial, With'the saw held in this adjustment, and when the grinding wheel 39 rises, it will grind the wall I59 radially. This wall may be ground at a right angle to the face of the saw, as is the usual practice, but could be ground at a transverse inclination, by angularly adjusting the bracket I33. The periphery 44 will grind the wall I6I. After each grinding action, the pawl I06 advances the circular saw a step equal to the horizontal length of the tooth and the next tooth is ground. This operation is repeated until all teeth are ground The plate I30 may be moved horizontally to the right with relation to the grinding wheel, and the radial lines I60 remain in the same position, since the saw has not been turned. The wall I59 of the tooth ISO to be ground is radial but inclined with respect to the perpendicular face 42, as indicated by the line I60, and when the grinding wheel rises and cuts the wall I59, such wall will be cut back upon the line I60, to provide a, rake, having an angle corresponding to the angle between the lines I60 and IE0. The grinding operations are illustrated in, Figures 26 and 2'7. A11 other parts of the apparatus remain identical with those shown and described in connection with the first form of the invention, and the operation of such parts are identical with that of the first form of the invention.

It is to be understood that the forms of our invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in thesize, shape, and arrangement of parts, may be resorted to, without departing from the spirit of our invention and the scope of the subjoined claims.

Having thus described our invention, what we claim is:

1. A saw sharpening machine, comprising a support, a rotary grinding wheel, a saw holding device to position the saw axially of the rotary grinding wheel, a member carrying the rotary grinding Wheel to shift the same into and out of engagement with the teeth of the saw, means to move the member, means to drive the rotary grinding wheel, a pawl to engage the teeth of the saw, an eccentrically pivoted disc to contact the pawl during a portion of its stroke to hold the pawl out of engagement with the saw tooth during such stroke,and means to move the pawl with relation to the disc to advance the saw.

2. A saw sharpening machine, comprising a support, upstanding connected plates arranged above the support and having a recess between them to receive the saw arranged on edge with .its teeth lowermost, a rear support plate secured to the bottom of the upstanding plates, a front support plate secured to the bottom of the upstanding plates and spaced from the rear support plate to form a passage, a disc eccentrically pivotally mounted upon the rear support plate and extending to the passage, a transverse rotary grinding wheel arranged near the passage, means to raise and lower the grinding wheel, means to drive the grinding wheel, a pivoted pawl arranged beneath the disc to contact therewith for a por- 19 tion of its stroke and adapted to engage the teeth of the saw, and means to move the pawl.

3. A saw sharpening machine, comprising a support, a substantially horizontal shaft mounted upon the support, means to drive the shaft, a vertically swinging carriage pivotally mounted upon the shaft, a spindle mounted upon the carriage and arranged substantially parallel with the shaft, means to drive the spindle from the shaft, a second substantially horizontal shaft mounted upon the support, means to drive the second shaft, a saw holding device mounted upon the support above the grinding wheel, means to move the carriage including a, cam mounted upon the'second shaft, a pawl arranged beneath the saw holding device to engage the teeth of the saw, an operating device having the pawl pivotally mounted thereon, and a cam mounted upon the second shaft to actuate the operating device.

4. A saw sharpening machine, comprising a support, a substantially vertical shaft mounted upon the support and extending above the same for insertion within the chuck of a drill, a second shaft mounted upon the support and driven from the substantially vertical shaft, a carriage pivotally mounted upon the second shaft, a rotary spindle mounted upon the carriage, a grinding wheel mounted upon the spindle, means for driving the spindle from the second shaft, a cam shaft driven from the substantially vertical shaft and mounted upon the support, means to move the carriage in one direction including a cam mounted upon the cam shaft, a pawl to engage the saw teeth and advance the saw, means to operate the pawl including a cam mounted upon the cam shaft, and a saw holding device arranged in cooperative relation to the grinding wheel.

5.A saw sharpening machine, comprising a support, a saw holding casing having a recess to receive the saw arranged on edge teeth down, said recess having a bottom provided with a passage, a holding member extending into the recess to engage the upper edge of the saw, means to mount the casing upon the support, a grinding wheel arranged beneath the casing for movement into the passage to engage the teeth, means to raise and lower the grinding wneei, means to drive the grinding wneei, and means engagin the saw teeth to advance the saw.

6. A saw sharpening machine, comprising a support, a substantially vertical shaft mounted upon the support and extending above the same for insertion within the chuck of a drill, a second shaft mounted upon the support, means to drive the second shaft from the substantially vertical shaft, a pivoted carriage arranged near the second shaft, a rotary grinding wheel carrying spindle mounted upon the carriage, means for driving the spindle from the second shaft, a cam shaft, means to drive the cam shaft from the substantially vertical shaft, means to move the carriage in one direction including a cam mounted upon the cam shaft, means to hold the saw in a position near the grinding wheel, a pawl to engage the saw teeth and advance the same,

and means to operate the pawl including a cam mounted upon the cam shaft.

7. A saw sharpening machine, comprising a support, a substantially vertical drive shaft mounted upon the support, a substantiall horizontal second shaft mounted upon the support, means to drive the second shaft from the substantially vertical shaft, a carriage pivotally mounted upon the second shaft to swing substantially vertically, a rotary grinding wheel amaeso carryingspindle mounted uponthe carriage, means for" drivihg the spindle from the second shaft, asubstantiallyhorizontal cam! shaft arranged beneath the carriage; means trpdrive the camshaftfrom the substantially vertical shaft, a cam to move the carriage and mounted upon the cam shaft, a saw holding device arranged near the carriage, a pawl. device to engage the teeth of the saw, and a cam to operate the pawl device and-mounted upon the cam shaft.

8. A'- saw' sharpening" machine, comprising a support; a substantially vertical drive shaft mounted upon the support, a substantially horizontal second shaftv mounted upon the support, means to drive the second shaft from the substantially vertical shaft, a vertically movablecarriage arranged near the second shaft, a rotary grinding wheel carrying spindle mounted upon the carriage, means for driving the spindle from the seconds-haft, a substantially horizontal cam shatt arranged beneath the carriage, means to drive the cam shaft from the substantially verticali shafit, an. adjustable element mounted upon the carriage, a cam: mounted upon the cam shaft to engage the.- element, saw holding means arranged near and above; the spindle, a pawl device: to engage the: saw teeth, and a cam-tooperate the pawl device and mounted upon the cam shaft.

9; AI saw sharpening machine, comprising a support to be mounted upon the table of a drill press, saidsupport having a substantially horizuntal' top provided; with an: opening, a substantially vertical bracket arranged above the top, means to horizontallyangularly adjustably mount the. bracket upon the top, a guide device for receiving an elongated saw with. the teeth of the saw lowermost and next. to the opening, means to vertically angul'arly adjustably mount the guide upon the bracket, a substantially vertical shaft mounted upon the support and extending above the support for insertion within the chuck of. the: drill press, saw sharpening? means mounted upon the support beneath the top, means to drive the saw sharpening meansfrom the substantially vertical, shaft, and saw feeding means mounted upon the support beneath the top and. driven from the substantially vertical shaft.

10. A saw sharpening machine, comprising a support to be mounted upon the table of a drill press, said support having a substantially horizontal top provided with an opening, a substantially vertical shaft mounted upon the support and projecting above the support for insertion within the chuck of? the drill press a guide casing arranged above the top and including a bottom provided between its ends with a passage arranged near the opening, said guide casing receiving an elongated saw on edge with its teeth arranged lowermost to contact with the bottom, a guide plate vertically adjustably mounted Within the casing to engage the top edge of the saw and projecting above the casing, saw sharpening means mounted upon the support beneath the top and including an element moveable into and out of engagement with the saw teeth through the opening and passage and driven from the substantially vertical shaft, and saw feeding means mounted upon the support beneath the top and including an element to en gage the teeth of the saw through the passage and driven from the substantially vertical shaft.

11. A saw sharpening machine, comprising a casing having a bottom provided with an opening; the casing receiving an elongatedsaen arranged on edge with its teeth in the lowermost position, an eccentrically pivoted: disc. disposed adjacent to: the bottom, andionening; a pawlgam ranged beneath the; disc and carried by the: op erating means, means to move: the pawh into emgagement: with the disc and'fronr such. engages ment. into the opening to engage the: sawtooth: and sharpening means moveable: into; engage,- mentwith the saw: teeth throughthe opening;

I2. A. saw sharpening machine, comprising: a uide device for receiving: a saw andhavingan opening: adjacent to. the teeth of the: saw, an eccentrically pivoted disc disposed; adjacent to the. opening; a pawl arranged upon, one side-of the. andcarried. by the operating means, means, to move the, pawl. into engagement with the: disc. and from such engagement; into. the opening;- to engage the saw teeth, sharpening means moveable into, the opening engagement with the saw teeth: through the opening, and means tohold the saw against improper moves merit during the sharpening operation.

1 3. A saw sharpening machine comprising a support, having an opening; a, saw-guide device receiving an elongated saw, mean-sto. angularly' adjustably mount the saw: guide upon the sup, port, an arm carried by the saw guide and: oxtending through the opening in the support, a clamp arm extending through the opening inthe support: and engaging the saw within the saw guide, means to pivotaliy mount the clamp arm upon said arm, a. spring to move the pivoted clamp arm in one direction, means to engage the saw and feed the same, and saw sharpening means. movable into. and out of engagement with the saw teeth.

MLA saw sharpening machine comprising a support, a rotary grinder carrying spindle arranged near the support and" extending longitudinally oi the support, means to drive the spindle and move thesame toward and from the support, a plate mounted upon the support. adjustable means connecting the plate with the support sothat the plate may be shifted longitudinally of the spindle, and means to mount a circular saw upon the plate so that its axis of rotation is disposed'transversely of the spindle. and means to turn the saw.

15. A saw sharpening machine comprisinga support, a rotary grinder carrying spindle arranged near the support and extending longitudinally of the support, means to drive the spindle and move the same toward and from the support, a plate mounted upon the support and having an opening transversely of the spindle, adjustable means connecting the plate with the support so that the plate may be shifted longitudinally of the spindle, a stud adjustably mounted. within the opening of the plate, an adapter mounted upon the stud, a nut carried by the stud and engaging the adapter so that the stud may be clamped to the plate, the adapter receiving thereon a circular saw and holding the saw so that its axis of rotation is transversely of the spindle, and resilient means carried by the stud and engaging the circular'saw.

16. A saw sharpening machine, comprising a device forreceiving and holding a saw, sharpening means movable into and out of engagement with the saw teeth, a pawl to engage the saw teeth, an eccentrically pivoted disc arranged to cover the pawl and have its side face contact with the free end of the pawl, and means separate 13 from the disc to shift the pawl generally radially with respect to the disc so that the free end of the pawl will clear the disc and engage with the tooth of the saw.

17. A saw sharpening machine, comprising a 5 support having an opening in its top, a saw holding device mounted upon the support above the top of the support for holding a saw inverted with its teeth next to the opening, a swinging carriage mounted upon the support and arranged beneath the top and the saw, a rotary grinder mounted upon the swinging carriage and arranged beneath the top and saw for movement into the opening of the top, a drive shaft mounted upon the support beneath the swinging carriage, a cam mounted upon the drive shaft to raise the carriage, a pivoted lever mounted upon the support beneath the top, a pawl carried by the pivoted lever to enter the opening in the top and engage the tooth of the saw, a cam mounted upon the drive shaft and engaging the pivoted lever, and means to drive the rotary grinder.

HENRY KERSHAW. ALBERT F. PITYO. HARRY BUTTERFIELD.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 14 UNITED STATES PATENTS Name Date Rich Dec. 10, 1867 Markland May 11, 1869 Medearis Aug. 28, 1877 Edge June 9, 1891 Rhodes Sept. 5, 1893 Daniels May 26, 1908 Wardwell Aug. 8, 1916 Armstrong et a1. Apr. 17, 1923 Kramer Mar. 11, 1924 Nosan Sept. 14, 1926 Hawkins May 17, 1927 Schultz Feb. 21, 1928 Collier Apr. 17, 1928 Pribnow June 10, 1930 Mathieu May 19, 1931 Hart May 24, 1932 Jirka May 16, 1933 Roxll Feb. 7, 1939 Knowles June 17, 1941 Dale Dec. 23, 1941 Underwood Nov. 9, 1943 Collier Feb. 29, 1944 Daggett Aug. 22, 1944 Hively Aug. 19, 1947 FOREIGN PATENTS Country Date Great Britain Jan. 22, 1931 

